Agriculture: Pear Pest Management Guidelines

General Properties of Fungicides Used in Pears

Common name (trade name) Chemical class Activity Mode of action (FRAC number)1 Resistance potential Comments
Aureobasidium pullulans (Blossom Protect) biological contact various (—) low  
Bacillus subtillis (Serenade Max) microbial contact various (—) low  
bordeaux inorganic contact multi-site (M1) low  
copper inorganic contact multi-site (M1) low  
cyprodinil (Vangard) anilinopyrimidine mostly contact; slightly systemic single-site (9) high  
difenoconazole/cyprodinil (Inspire Super) DMI2/anilinopyrimidine contact, systemic two, single-site modes of action (3/9) medium  
dodine (Syllit) guanidine systemic (local) unknown (U12) medium slow resistance by limiting applications to one per season or tank mixing with another fungicide
fenarimol (Rubigan, Vintage) DMI2-pyrimidine systemic6 (local) single-site (3) high  
fosetyl-al (Aliette) phosphonate systemic unknown (33) low  
kresoxim-methyl (Sovran) QoI3 contact, systemic6 single-site (11) high  
lime sulfur inorganic contact multi-site (M2) low incompatible with most other pesticides
mancozeb (Dithane, Penncozeb, Manzate) carbamate (EBDC)4 contact multi-site (M3) low  
oxytetracycline (Mycoshield, Fireline) antibiotic contact protein synthesis (41) high  
Pseudomonas fluorescens (Blight Ban) biological contact various (—) low  
pyrimethanil (Scala) anilinopyrimidine mostly contact: slightly systemic single-site (9) high  
pyraclostrobin/boscalid (Pristine) Qol3/SDHI7 contact, systemic two, single-site modes of action (7/11) high  
streptomycin (Ag-Streptomycin, Agri-Mycin, Firewall) antibiotic systemic protein synthesis (25) very high  
sulfur inorganic contact multi-site (M2) low toxic to predatory mites and parasites
tebuconazole (Tebuzol) DMI2 systemic (local) single-site (3) high  
tebuconazole/trifloxystrobin (Adament) DMI2/Qol3 systemic two, single-site modes of action (3/11) medium  
thiophanate-methyl (Topsin-M, T-Methyl, Incognito) MBC8 systemic (local) single-site (1) very high toxic to earthworms with repeated usage
trifloxystrobin (Flint) QoI3 contact, systemic6 single-site (11) high  
triflumizole (Procure) DMI2-imidazole systemic6 (local) single-site (3) high  
ziram carbamate (DMDC)5 contact multi-site (M3) low  
1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions. Fungicides with a different group number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode-of-action group numbers 1, 4, 9, 11, or 17 before rotating to a fungicide with a different mode-of-action group number; for fungicides with other Group numbers, make no more than two consecutive applications before rotating to fungicide with a different mode-of-action group number.
2 DMI = demethylation (sterol) inhibitor
3 QoI = quinone outside inhibitor (strobilurin)
4 EBDC = ethylene bisdithiocarbamate
5 DMDC = dimethyl dithiocarbamate
6 Generally considered to have systemic action based on performance data but not yet proven experimentally.
7 SDHI = succinate dehydrogenase inhibitor
8 MBC = methyl benzimidazole carbamate
= No information

Acknowledgment: Adaskaveg et al., 2017. Efficacy and Timing of Fungicides, Bactericides, and Biologicals for Deciduous Tree Fruit, Nut, Strawberry, and Vine Crops (PDF).

Text Updated: 11/12